WASHINGTON — Secretary of State John Kerry on Thursday called on the UN Security Council to move swiftly to approve a US-Russian deal to eliminate Syria’s chemical weapons, saying there is no time to argue with those who remain unconvinced that the Syrian regime carried out a chemical attack last month that killed hundreds.
Kerry didn’t mention Russian President Vladimir Putin, but his remarks were a clear attempt to rebut Putin’s statement that Russia has strong grounds to believe that Syrian rebels — not President Bashar Assad’s regime — were responsible for the Aug. 21 attack.
Speaking at a conference, Putin said, ‘‘We have every reason to believe that it was a provocation, a sly and ingenious one.’’ He said those who perpetrated the attack relied on ‘‘primitive’’ technology, using old Soviet-made ammunition no longer in the Syrian army’s inventory.
While a recent report by UN inspectors did not ascribe blame, the United States, Britain, France, and others believe that the report’s findings offer conclusive evidence that the attack was conducted by the Syrian military. Assad, in an interview this week with Fox News Channel, denied that his regime was responsible for the attack.
The United States, Britain, and France pointed to evidence in the report — especially the type of rockets, the composition of the sarin agent, and trajectory of the missiles — to declare that Assad’s government was responsible. Moreover, they argue that there is no evidence that opposition forces possess sarin gas.
‘‘So there you have it. Sarin was used. Sarin killed,’’ Kerry said.
‘‘The world can decide whether it was used by the regime, which has used chemical weapons before — the regime which had the rockets and the weapons — or whether the opposition secretly went unnoticed into territory they don’t control to fire rockets they don’t have, containing sarin that they don’t possess, to kill their own people.
‘‘And then, without even being noticed, they just disassembled it all and packed up and got out of the center of Damascus controlled by Assad. Please. This isn’t complicated.’’
Kerry’s comments in support of the UN report followed weeks of US skepticism about whether the UN inspectors would be able to make valid determinations, mainly because of the length of time that transpired between the attack and when the inspectors were given access to the site.
The United States wants a new Security Council resolution now under discussion to make the US-Russian agreement reached last week in Geneva legally binding in a way that is verifiable and enforceable.
The United States and Russia are arguing over putting the resolution under Chapter 7 of the UN Charter.
Chapter 7 deals with threats to international peace and security and has provisions for enforcement by military or nonmilitary means, such as sanctions.
Russia, which already has rejected three resolutions on Syria, would be expected to veto a UN move toward military action, and US officials have said they do not contemplate seeking such an authorization. Russia holds veto power in the Security Council, along with the other permanent members, the United States, China, Britain, and France.
‘‘We really don’t have time today to pretend that anyone can have their own set of facts approaching the issue of chemical weapons in Syria,’’ Kerry said. ‘‘This fight about Syria’s chemical weapons is not a game. It’s real. It’s important. It’s important to the lives of people in Syria, it’s important to the region, it’s important to the world that this be enforced — this agreement that we came out of Geneva with.’’
Putin expressed optimism when asked whether he trusts Assad to fulfill Russia’s plan for Syria to surrender its chemical weapons and avoid a US strike. He said Damascus’s actions so far have given reason to believe the initiative will be implemented.
‘‘I can’t be 100 percent sure that we will bring it to the end, but what we have seen in the past few days has given us confidence that it will be accomplished,’’ Putin said.
Responding to a question about what would happen if Assad’s government breaks its pledge, Putin said ‘‘we have no reason to believe they would fail to fulfill their obligations.’’
“We will look into that if they would, but it’s premature to talk about it,’’ he added.
Asked if Syria’s list of its chemical arsenals could be trusted, Russian Prime Minister Dmitry Medvedev said Damascus will ‘‘have to do its best to convince the international community that the list they present is complete and that efficient verification and control can be provided.’’
Speaking in Moscow, Medvedev sought to emphasize that Russia shouldn’t be held solely responsible for the plan’s success.
‘‘The responsibility [for success of the plan] has not shifted to the Russian federation,’’ Medvedev said.
‘‘It’s our joint responsibility’’ and not ‘‘the sole responsibility of the Russian federation.’’
Putin insisted that Russia strongly opposed a US attack on Syria because it would violate basic principles of international law and undermine the UN’s role, not because it was trying to keep Assad in power.